Anyway i can lose weight without exercise?

Ok well im 13 yrs old andi feel really insecure about my weight i weigh 130lb and i am 5 5", i have some chub on my body that i feel insecure about, and my mom is about 2" in shorter than i am and weighs less than i do and is only 34, i have little stretch marks on my sides and on the upper part of my thighs, i have chubby cheeks and chubby hands and fingers i am not into sports i occasionally go on hikes in the summer and ride bike with friends but nothing major, i dont really eat fast food alot and i dont snack alot but i wanna know if there is anything i can do like little exercises at home to maybe help? or a diet ? my mom says that its just baby fat and it will go eventually and i wonder if it ever will. but my mom says that i have stretch marks bcuz im growing to fast and she has sown me her stretch marks and they just fade into her skin but she says that they stay like a scar but she said she got them from having kids and i feel that im 13 and i have them it makes me feel insecure so is there anything i can do to make me feel better about my image, or something that can get rid of my stretch marks or loses a little weight?